Oh, all the estate sales I go to are run (and posted) by third parties, who do it as a business, for a percentage of the sales. The heirs are nowhere to be found -- they got a first pass through the house a few days prior to grab anything sentimental, and they'll show up a few days later when the business has been transacted. But the folks running the sale are professionals.
Which means they should know better. And some of them do -- I have a few local favorite companies, where I know they'll keep things together, they're good about finding manuals in file cabinets and putting them with their respective items, etc. I'm usually happy to pay their asking price, because they're interested in seeing the items go to good homes and get reused, and take care accordingly.
But, likewise I have some "un-favorites", one who was notorious for sticking price-tags on screens. I might've finally trained them out of this when I told them I'd only pay their asking price for a particular piece of test equipment if they could remove the sticker without damage. They removed it, the already-degrading plastic screen was obviously fucked by the adhesive, they exchanged awkward glances with each other, and I walked away. Maybe they'll keep that in mind on the next sale they run.
Meh. Maybe it is a cultural difference, we have different manners outside the USA. Your business is rather vulgar in the UK context, that of a parasite or a greedy gannet. There would be no honour in selling the estate items to your sort, setting light to everything or giving it to sensible charities would be far preferable.
As exemplified by what is going on in the Middle East, the USA has different values to the rest of the world, so don't take this criticism as a slight, just don't come here and expect to be liked for what you are doing.